I live in Glebe and work in the Sydney CBD. At work I've always got full coverage/service, I hardly ever roam unless I'm in the belly of my office building. At home, it clings to 3G and roams rarely. No problems with call drop outs or anything but I only ever have about one bar of service. Which is a bit weird, but nothing to complain about really. My last bill (I've had my iPhone about a month and half on Three) only had roaming charges totalling 3cents.
